filter grid based on conbobox ona form

public class FormRun extends ObjectRun
{
    SysFormSplitter_X verticalSplitter;
    QueryBuildRange                qbr;
}


public void executeQuery()
{
    if(BusinessUnit.text() != "")
    {
        qbr.value(queryValue(BusinessUnit.text()));
    }
    else
    {
        qbr.value(SysQuery::valueUnlimited());

    }

    super();
}




public void init()
{
    super();
    qbr= this.query().dataSourceTable(tableNum(VendTable)).addRange(fieldNum(VendTable, InventSiteId));

}


public void lookup()
{
    Query                   query = new Query();
    QueryBuildDataSource    queryBuildDataSource;

    SysTableLookup  sysTableLookup = SysTableLookup::newParameters(tableNum(OMOperatingUnit), this);
    ;
    queryBuildDataSource = query.addDataSource(tableNum(OMOperatingUnit));

    sysTableLookup.addLookupfield(fieldNum(OMOperatingUnit, OMOperatingUnitNumber));
    //sysTableLookup.addLookupfield(fieldNum(CustVendExternalItem, ExternalItemId));

    queryBuildDataSource.addRange(fieldNum(OMOperatingUnit, OMOperatingUnitType)).value(queryValue(OMOperatingUnitType::OMBusinessUnit));
    sysTableLookup.parmQuery(query);
    sysTableLookup.performFormLookup();

    super();
}

---------------------------------------------------------------------------------------------------------------
public boolean modified()
{
    boolean ret;

    ret = super();
    VendTable_ds.executeQuery();
    return ret;
}